1. Field of the Invention
The present invention relates to apparatus for use in creating three-dimensionally encoded photographic images. More particularly, the present invention pertains to an adapter for generating such images with a camera having a single lensing system.
2. Description of the Prior Art
Three-dimensional photography adds much to a viewer's experience. In addition to providing added entertainment value, the appreciation of depth within a field-of-view can be essential in camera-assisted procedures. For example, video cameras employed by operating physicians during microsurgery provide much-needed information concerning the front-to-back, in addition to the side-to-side, geometry of an anatomical area.
In the prior art, the creation of a three-dimensional viewing effect on a two dimensional screen has required and relied upon the creation of two two-dimensional parallax inputs that the brain is capable of processing in combination to create a third sensory dimension, depth. In a human being (and for that matter, in most animals), such parallax inputs result as a consequence of physical separation between two simultaneously-operative visual pickups (i.e. the left and right eyes) that enables the viewer to pick up images of a field-of-view from somewhat-different perspectives.
The recording of visual information for subsequent playback in a manner that permits the brain to derive depth involves detecting and, possibly, recording two two-dimensional images of a single field-of-view taken from positions that mimic the relative perspectives of a viewer's right and left eyes. Various projection and playback devices and systems are available to direct the individual images to the viewer's right and left eyes so that the parallax images are essentially simultaneously viewed by the corresponding human pickups and the brain can then derive depth. The various systems of the prior art for recording the requisite pair of two-dimensional parallax images are characterized by pairs of visual processing channels. For example, in video recording systems (e.g. home video cameras of the CAMCORDER type), both separate cameras and cameras that employ a pair of lensing systems and independent pickup devices (such as charge coupled devices) are employed to generate separate right eye and left eye images. The two images are then electronically interlaced in accordance with a recognized video format (e.g. NTSC) for viewing by, for example, a headset or glasses that include out-of-phase shuttering mechanisms to guarantee that only the proper image field is viewed by the wearer's right and left eyes.
Three-dimensional motion film photography employs separate cameras oriented with respect to one another to recreate the relative right and left eye perspectives. The cameras may be bracketed or strapped together at a predetermined angle. The two images are then projected through orthogonally-polarized filters onto a common two-dimensional screen to produce a "ghosted" composite image. By viewing the composite image through a pair of glasses whose right and left lenses are of opposite polarizations (matching the polarizations of the appropriately recorded images), each image is input through the "correct" eye, allowing the viewer's brain to process the received visual information properly.
Recording three-dimensional image information thus has involved both cumbersome and expensive techniques. As a result, the application and development of three-dimensional image recording and film photography have been hampered by production expenses that include systems having multiple expensive components including cameras, lenses and sensors.